Adjustable cartridge case gage



Oct. 5, 1965 L. E. WILSON 3,209,461

ADJUSTABLE CARTRIDGE CASE GAGE Filed Aug. 12, 1963 2 Sheets-Sheet 1 LLOYD E. WILSON INVENTOR Oct. 5, 1965 E. WILSON 3,209,461

ADJUSTABLE CARTRIDGE CASE GAGE Filed Aug. 12, 1963 2 Sheets-Sheet 2 FIG 9 F G O FlG FIG l2 ATTORNEYS United States Patent 3,209,461 ADJUSTABLE CARTRIDGE CASE GAGE Lloyd E. Wilson, 404 Pioneer Ave., P.0. Box 324, Cashmere, Wash. Filed Aug. 12, 1963, Ser. No. 301,383 14 Claims. (Cl. 33-174) This invention relates to a new and useful concept in an adjustable cartridge case gaging means and more particularly to a cartridge case gage which is adjustable to the dimensions of a particular rifle and which minimizes working of the cartridge case brass.

In the making of rimless ammunition and in the chambering of rifles for such type of ammunition, a close relationship is maintained between the cone-to-head length of the cartridge and the same dimension, sometimes known as headspace, in the chamber. Such close relationship is required because uniform ignition depends on this fit, since the shoulder in the chamber supports the cartridge against the blow of the firing pin. In many rimless calibers, the cone-to-head length of a new cartridge will be slightly greater than the cone-to-bolt face length (headspace) of a correctly chambered rifle. Thus there may be some feel in closing the bolt on a new cartridge.

In belted calibers, proper ignition does not depend on the cone-to-head length of the cartridge relative to the chamber. Instead, the firing pin thrust is taken by the belt against its seat in the chamber. The upshot of this fact is that the cone-to-head length of the belted cartridges is of no consequence so far as ignition is concerned. Thus the factory can be, and in many instances is, quite tolerant regarding the fit of the cartridge beyond the belt recess. The factory is concerned only with the firing of the cartridge once, and because new brass will stand a lot of stretching. The reloader, however, is concerned with the fit of the cartridge beyond the belt because the less the brass is worked in reloading and firing, the longer it will last.

In the first belted calibers, the shoulder angle was so slight that cases had much less tendency to stretch, and perhaps pull apart, than they would in a situation in which the case shoulder has a more abrupt angle. With the advent of later belted calibers, i.e., the 7 X 61, the Weatherbys, the 264, 300 and 338 Winchester Magnums, to mention a few, more abrupt shoulders have brought with them a tendency for the case to stretch and pull apart. To complicate matters, different rifles of the same caliber regardless of make will be found to vary greatly in chamber dimensions forward of the belt.

This invention seeks to remedy those problems which inhere in rifles using belted type ammunition. With this gage the rifle owner can readily adjust a case gage to fit his particular rifle and then resize his case accordingly. The general solution to the problems enumerated is achieved by a cylindrical, heavy wall, gage body. This body is bored and reamed to align the case of the head end and includes on the interior thereof a movable insert bored and reamed to align and support the shoulder end of the case. The gage body is bored at a larger diameter at the neck and cone end of the gage in order to receive a cylindrical insert which adjusts to the headspace of a particular rifle. At least one set screw is located in the wall of the main body so that it can be tightened to hold the insert in the desired position. An alternative embodiment of this invention permits the use of inserts at both head and cone ends of the gage.

Accordingly it is a feature of this invention to provide an adjustable cartridge case gage which is simple in design, inexpensive to produce and convenient to use.

Another feature of this invention is to provide an adjustable cartridge case gage which enables the reloader to visually observe the amount of working that has been done on the shoulder.

Yet another feature of this invention is to provide an adjustable cartridge case gage which minimizes working of the brass in the resizing of cartridge cases.

Still another feature of this invention is to furnish an adjustable cartridge case gage which extends the usable life of cartridge cases.

Other features and advantages of this invention will become apparent in the following detailed discussion, appended claims and drawings forming a part of this invention.

On the drawings:

FIGURE 1 is an enlarged, slightly exaggerated, longitudinal, cross-section view of this invention;

FIGURE 2 is an enlarged view in perspective and slightly exaggerated in some details to illustrate the head of a case as inserted in the gage;

FIGURE 3 is a partial view in perspective of the cone or neck end of the gage also with the details slightly exaggerated in order to more clearly illustrate its various features and to show a case neck protruding from the insert;

FIGURE 4 is a cross-sectional, longitudinal view of an alternative form of this invention for measuring headspace only;

FIGURE 5 is an enlarged view in perspective of the head end of the gage of FIGURE 4 with the details thereof slightly exaggerated for clarity of illustration; 1

FIGURE 6 is a longitudinal, cross-sectional view of a second alternative embodiment of the invention and which embodiment has double inserts for reasons which will be explained later;

FIGURE 7 is an enlarged, partial View in perspective showing the head end insert of the gage of FIGURE 6;

FIGURE 8 is an enlarged partial view in perspective of the neck insert end of the gage of FIGURE 6;

FIGURES 9 through 12 illustrate the principles in the use and operation of the gage of FIGURES 1 through 3 with the proportions thereof exaggerated even more in order to clarify such use and operation; and

FIGURE 13 is a partial cross-sectional view showing that the inserts of the preferred and alternative embodiments of the gage may be threaded into the body of the gage as an optional manner by which the inserts may be employed in the various forms of the invention.

Referring now to the drawings, in particular FIGURES 1 through 3, it will be seen that the gage body, generally designated by the number 10, is an elongated, heavy walled, cylindrical body which for purposes of clarification only is approximately two and one-half inches long and roughly an inch in overall outside diameter. Beginning at the head end and working towards the insert end, it will be seen that the gage has a belt recess 12 with radially, inwardly, oifset belt surface 14. Extending forwardly is the case body recess 16 which extends from the belt surface 14 to the radially, outwardly, extending offset insert shoulder 18. An insert recess of slightly larger diameter than the case body recess 1y is defined by the insert surface 20. It should be noted that the offset belt surface does not, in any of the gages, actually touch or abut the belt of the cartridge case.

For purposes of illustration, the gage body 10 is shown to have a head end 15 and an insert end 22. Head end 15 has a high surface 24 and a low surface 26. Each high and low surface 24 and 26 extends over approximately half of the head end surface area, the division being generally along a diameter line to form the offset step surface 28. The step surface 28, the purpose of which will be explained more fully hereinafter, is shown in slightly exaggerated form in order to accurately convey a detailed understanding of the invention. In actual practice, the offset step surface 28 is about .010 of an inch from high surface 24 to low surface 26. Similarly, insert end 22 has high surface 30 and low surface 32 defining step surface 34 generally along the diameter line.

The insert, generally designated by number 36, be short, cylindrical body designed to be accommodated in the insert cavity 20 in a close sliding type fit. Insert 36 has outer end 38 and inner end 40. The insert is formed to accommodate a particular caliber cartridge case. Thus it has neck cavity 42 and the cone cavity 44 with said cone cavity having an angle of slope conforming to the shoulder or cone angle of the particular case to be used in the rifle. The angle of the shoulder recess is formed as accurately as possible to conform to said cartridge case. Less accurately manufactured insert shoulder angles result in line contact gages which are not particularly desirable but which are within the scope of this invention. Insert 36 may be firmly held in place by set screws 46. Note that a small fiber pad 48 is inserted in the set screw opening between the screw and insert so that the outside surface of the insert will not he marred. A cartridge case 50 indicates the manner in which it is received in the gage.

FIGURES 4 and show a first alternative embodiment of the invention. This embodiment of the invention gages cartridge headspace only as opposed to gaging both length and headspace as achieved by the preferred form. This alternative structure, generally designated by the number 60, is also a thick-walled cylindrical body having head end 62 and neck or insert end 64. Head end 62 has the high and low surfaces 66 and 68 for determining Whether or not the case headspace is within the correct dimensional range. Thus there is a maximum or high surface 66, a minimum or low surface 68 and the offset step surface 70. Note that in this embodiment there are two offset surfaces 70 formed on chord lines to define what might be equated to a shallow groove extending across the head end of the gage body. It will be understood that the upper and lower surfaces could be formed as in the preferred embodiment or formed as shown in this first alternative embodiment. A recessed belt surface 72 is formed beyond the depth of the belted portion of the head end of the cartridge. It is important to note that in all of the gages of this invention the belt surface is formed not to abut the belt. In fact the belt surfaces are formed to provide substantial clearance between the belt and the belt surface of the gage. The portion of the gage body surface 76 adjacent the belt recess is closely dimensioned to the case body at this point in order to provide the alignment desired. As in the preferred embodiment, roughly one half of the interior length of the overall gage is formed on an increased diameter over that of either the body cavity or belt cavity to form the insert surface 80 defining the insert cavity. The offset insert shoulder 78 is naturally formed as a result of this configuration.

The insert, generally designated by the number 82, is similar to the insert in the preferred embodiment. Said insert 82 has neck end 86 and body end 84. The neck cavity is formed by neck surface 88, the shoulder cavity by cone surface 90, and a short expanse of body cavity formed by the body surface 92. Set screws 94 are provided in a series of three or four since this embodiment of the gage is designed to accommodate a number of calibers of rifle. For this reason it is necessary that the inseft cavity defined by the insert surface 80 be somewhat longer or deeper than that required in the embodiment shown in FIGURES 1 to 3. Hence, it is necessary to have a plu rality of screws in order to properly lock the insert at its desired setting. As with the preferred form, each of the set screw openings is provided with a resilient fiber set screw pad 96 to avoid marring the sliding surface of the insert when the screw is tightened down on the insert.

This form of the invention, as mentioned above, has as its purpose to gage headspace for a plurality of rifle calibers. A number of different caliber rifles use cartridges in which the dimensions of the head or belted portion of the case are the same. However, differences in the cone and neck portions of the cartridges and variations in overall length require interchangeable inserts. It will be seen, because of this interchangeability of the inserts, that this is a more flexible form of the gage insofar as it does gage headspace but not overall length. Its principles of use, however, are identical to that of the preferred form.

FIGURES 6, 7 and 8 show the details of a second alternative embodiment of this invention. It, too, has a thickwalled cylindrical body, generally designated by the number 100, and having head insert end 102 and neck and shoulder insert end 104. It will be observed that this form of the gage has a straight unobstructed inner surface 101. Head end insert 106 is approximately half as long as the main gage body 100. The head end insert on its outer end has upper surface 108 lower surface 110 and the offset step surface 111. Insert 106 has formed therein the belt surface 112 defining the belt cavity, the belt surface 114, and the cartridge body surface 116 defining the body cavity. Said insert 106 terminates inside the gage body at inner end 118.

The neck and shoulder insert, generally shown by the number 120, is of shorter length than the head end insert. It has outer end 124 and inner end 122 and like the inserts of the other forms of the invention has neck surface 126, shoulder surface 128 and a short length of body surface 130. It is to be noted that it is the neck end of the main body gage 100 which is provided with an offset step surface for gaging overall length. Thus the neck and shoulder end 104 of the main body is provided with upper surface 132 and lower surface 134 to define the offset step surfaces 136. Again it should be mentioned that the gage steps may be formed on chord lines or on a diameter line as shown in the preferred form. The head end insert 106 is fixed in position by set screw having a fiber pad 142. In like manner the neck end insert has set screw 144 and pad 146.

Operation and use FIGURES 9 through 12 are enlarged and shown with greatly exaggerated dimensions in order that they may more clearly demonstrate the use and the operation of this invention. Thus these figures are in effect merely diagrammatic representations contained herein for the sake of clarity.

FIGURES 9 and 10 show how the position of insert 36 with relation to the neck end of the gage 10 has been set to correspond to the headspace of a particular rifle. In FIGURE 9 the insert 36 has been set in accordance with a master case, which could be a previously fired cartridge case from that particular rifle. FIGURE 9 indicates that the head end of the case is flush with the top step to indicate that the headspace dimension of the case is at a maximum. In order to ensure that the case which is being gaged will fit comfortably into the rifle chamber, case 50 is taken out of the gage and resized in order to reduce the headspace dimension. FIGURE 10 shows that when the case is reinserted in the gage, after the last resizing step, that the headspace has been reduced. In other words, the head end of the case is approximately between the steps or generally between minimum and maximum allowable tolerances for a proper fit of the case in the rifle to which the gage is set.

FIGURES 11 and 12 show the same gage set for a rifle in which the chamber has been made slightly deeper in the manufacturing process than the chamber of the rifle for which the gage of FIGURES 9 and 10 has been set. Thus it will be noted that the insert 36 in FIGURES 9 and 10 is in one position while the insert 36 in FIG- URES 11 and 12 is out slightly further to suggest the deeper chamber of the rifle which it is intended to gage. FIGURE 11 shows the case 50 as having the maximum allowable headspace by virtue of the fact that the head surface of the cartridge is flush with the upper surface. By removing the case from the gage and resizing slightly in a die and then reinserting in the gage, as shown in FIGURE 12, it will be seen that headspace has been reduced somewhat to bring the head end surface of the case between the steps.

In any event, the distance between the two upper steps of the gage shown in FIGURES 1 to 3 and 9 to 12 represent acceptable maximum overall length of a cartridge for the rifle to which the gage is set. The distance between the head end upper surface 24 and insert end lower surface 32 of the gage represents an acceptable minimum overall length of the case.

The embodiment of the invent-ion shown in FIGURES 4 and 5 can be seen to be designed for gaging headspace only. However, because of interchangeable inserts, it can be set to gage headspace of several calibers of rifles having the same head dimensions. The insert in this embodiment as in the preferred form is set or positioned by using a master case such as a case fired in the particular rifle for which the gage is being used. Similarly, the gage of FIGURES 6 to 8 has even more flexibility than the alternative embodiment shown in FIGURES 4 and 5. This gage determines both overall length and headspace for a wide range of calibers and head dimensions. Inasmuch as the inserts are interchangeable, the gage can be used for practically any caliber rifle. The gage is, however, designed for using a series of inserts at both ends to cover most popular makes of rifle regardless of caliber and head dimensions. A small number of gages with inserts will cover practically all calibers.

Using the preferred form of the gage as an example, the procedure for gaging a resized cartridge will now be described. First, note the position of the insert in the gage body. It should be well inside said body. The set screws are tightened only lightly. The fired case is dropped into the gage. The head should protrude. The case is pushed into the gage causing the insert to slip until the head of the case is even with the high surface of the gage. The straight edged instrument shown in FIGURES 2 or 3 should be used to force the case down until the head of the case is even with the upper step. It should be noted that the straight edge 52 should be resting on the head and not on the primer 51. Then the set screws are tightened to secure the insert. With this adjustment, the case gage is now adjusted to the chamber of a particular rifle. Resizing of subsequent cases should'be done so that the head will register between the upper and lower steps. In other words, a slight reduction in cone-to-head length is effected to permit closing of the bolt without undue effort.

When the gage has been set so that the head is flush or below the upper step, overall length can be checked by standing the gage with a cartridge case inserted on a flat surface head end down. If the neck rim or mouth registers above the upper step, the case is over length and should be trimmed down since overall length of the cases should not exceed the overall length of the gage.

FIGURE 13 shows an alternative method for adapting the inserts to the gage body by employing threads. Note .that set screws are still included. While a gage can be made in this manner, the use of threads does raise problems in the concentricity of the main gage body and the inserts.

The foregoing is consideredas illustrative only of the principles of this invention. Since numerous modifications and changes will occur to those skilled in the art, it is desired not to limit the invention to the exact construction and operation shown and described. Accordingly, all suitable equivalents may be resorted to which fall within the scope of the invention.

What is claimed is:

1. An adjustable cartridge case gage, comprising:

(a) an elongated, heavy walled, cylindrical body having a portion of its interior formed to receive the head and body of a cartridge case, said body also having a portion of its interior formed on an enlarged diameter to define an insert-receiving cavity, (b) a generally cylindrical insert means slidably engaged in said cavity, said insert means having its interior formed to the general configuration of the neck and cone portion of a cartridge case, (c) offset step surface means at each end of said body defined by upper and lower surface means, and (d) set screw means in said body for holding said insert means in a predetermined position.

2. An adjustable cartridge case gage, comprising:

(a) an elongated, heavy walled, cylindrical body having a substantial portion of its interior formed to the general configuration of the head and body part of a cartridge case, said body also having a substantial portion of said interior thereof formed on an enlarged diameter to define an insert-receiving cavity, (b) a generally cylindrical insert means slidably engaged in said cavity, said insert means having its interior formed to the general configuration of the neck and cone portion of a cartridge case, (c) offset step surface means at each end of the said body defined by generally parallel upper and lower surface means, and (d) set screw means in said body for holding said insert means in a predetermined position.

3. An adjustable cartridge case gage, comprising:

(a) an elongated, heavy walled, cylindrical body having a head end and an insert end, said body having a substantial portion of the head end of its interior formed to the general configuration of a belted type cartridge case and a substantial portion of the interior of the neck and shoulder end formed on an enlarged diameter to define an insert-receiving cavity, (b) a generally cylindrical insert means slidably engaged in said cavity and formed to receive the neck and cone portion of a cartridge case, (c) offset step surface means at each end of said body defined by generally parallel upper and lower surface means, and ((1) set screw means in said body for holding said insert means in a predetermined position.

4. An adjustable cartridge case gage, comprising:

(a) an elongated, thick walled, cylindrical body having a portion of its interior formed to receive the head and rear portion of a cartridge case, said body also having a portion of its interior formed on an enlarged diameter to define an insert-receiving cavity, (b) a generally cylindrical insert means slidably engaged in said cavity, said insert means having its interior formed to the general configuration of the neck and cone portion of a cartridge case, (c) at least one end of said body having an offset step surface means defined by upper and lower surface means, and (d) set screw means in said body for holding said insert means in a predetermined position.

5. An adjustable cartridge case gage, comprising:

(a) an elongated, heavy walled, cylindrical body having a substantial portion of its interior formed to the general configuration of the head and body part of a cartridge case, said body also having a substantial portion of said interior thereof formed on an enlarged diameter to define an insert-receiving cavity, (b) a generally cylindrical insert means slidably engaged in said cavity, said insert means having its interior formed to the general configuration of the neck and cone portion of a cartridge case, (c) ofi'set step surface means on at least one end of said body defined by generally parallel upper and lower surface means, and (d) set screw means in said body for holding said insert means in a predetermined position.

6. An adjustable cartridge case gage, comprising: (a) an elongated, heavy walled, cylindrical body having a head end and an insert end, said body having a substantial portion of the head end of its interior formed to the general configuration of a belted type cartridge case and a substantial portion of the interior of the neck and shoulder end formed on an enlarged diameter to define an insert-receiving cavity, (b) a generally cylindrical insert means slidably engaged in said cavity and formed to receive the neck and cone portion of a cartridge case, (c) offset step surface means on at least one end of said body defined by generally parallel upper and lower surface means, and (d) set screw means in said body for holding said insert means in a predetermined position.

7. An adjustable cartridge case gage, comprising: (a) an elongated, heavy walled, cylindrical body having a portion of its interior formed to receive the head and body of a cartridge case, said body also having a portion of its interior formed on an enlarged diameter to define an insert-receiving cavity, (b) a generally cylindrical insert means received in said insert-receiving cavity having its interior formed to the general configuration of the neck and cone portion of a cartridge case, (c) offset step surface means on one end of said body defined by upper and lower surface means, and ((1) set screw means in said body for holding said insert means in a predetermined position.

8. An adjustable cartridge case gage, comprising: (a) an elongated, heavy walled, cylindrical body having a substantial portion of its interior formed to the general configuration of the head and body part of a cartridge case, said body also having a substantial portion of said interior thereof formed on an enlarged diameter to define an insert-receiving cavity, (b) a generally cylindrical insert means movably engaged in said cavity, said insert means having its interior formed to the general configuration of the neck and cone portion of a cartridge case, (c) offset step surface means on one end of said body defined by generally parallel upper and lower surface means, and (d) set screw means in said body for holding said insert means in a predetermined position.

9. An adjustable cartridge case gage, comprising: (a) an elongated, heavy walled, cylindrical body having a head end and an insert end, said body having a substantial portion of the head end of its interior formed to the general configuration of a belted type cartridge case and a substantial portion of the interior of the neck and shoulder end formed on an enlarged diameter to define an insert-receiving cavity, (b) a generally cylindrical insert means,

10. An adjustable cartridge case gage, comprising: (a) an elongated, heavy walled, cylindrical body having a first insert end and a second insert end, (b) a first insert means movably received in said first insert end for receiving the head and rear body portion of a cartridge case and a second insert means movably received in said second insert end designed to receive the neck and shoulder portion of said cartridge, (c) first offset step surface means on the outer end of said first insert means, (d) second offset step surface means on the second insert end of said body, both said first and second offset step means being defined by upper and lower surface means, and (e) a plurality of set screw means in said body for holding said first and second insert means in predetermined positions within said body.

11. An adjustable cartridge case gage, comprising:

(a) an elongated, heavy walled, cylindrical body having a first insert end and a second insert end, (b) a first insert means for receiving the head and rear body portion of a cartridge case and a second insert means designed to receive the neck and shoulder portion of said cartridge, (0) first offset step surface means on the outer end of said first insert means, ((1) second offset step surface means on the second insert end of said body, and (e) a plurality of set screw means in said body for holding said first and second insert means in predetermined positions.

12. An adjustable cartridge case gage, comprising:

(a) an elongated, heavy walled, cylindrical body having a head end and a neck end, (b) means at said head end for receiving the head and rear body portion of a cartridge case and movable insert means at said neck end to receive the neck and shoulder portion of said cartridge case, (c) olfset step surface means on at least one of said ends, and (d) a plurality of set screw means in said body for holding said insert means in a predetermined position.

13. An adjustable cartridge case gage, comprising:

(a) an elongated, heavy walled, cylindrical body having a head end and a neck end, (b) first means at said head end for receiving the head and rear body portion of a cartridge case and movable insert means at said neck end to receive the neck and shoulder portion of said cartridge case, (c) offset step surface means, at least on said head end, and (d) a plurality of set screw means in said body for holding said insert means in a predetermined position.

14. An adjustable cartridge case gage, comprising:

(a) an elongated, heavy walled, cylindrical body having a head end and a neck end, (b) a generally cylindrical first insert means axially slidably received in said neck end of said body for receiving the neck and shoulder end of a cartridge case, (0) a second means at the head end of said body for receiving the head and rear body portion of a cartridge case, (d) offset step surface means at least on said head end of said body, and (e) a plurality of set screw means in said body for holding at least said first insert means in a predetermined position.

References Cited by the Examiner UNITED STATES PATENTS 1,602,645 10/26 Buckingham 33l74 1,873,067 8/32 Stromgren 33-181 2,383,348 8/45 Sink 33-174 2,585,521 2/52 Wandrus 33-174 2,592,409 4/52 Frankland 33-478 ISAAC LISANN, Primary Examiner, 

4. AN ADJUSTABLE CARTRIDGE CASE GAGE, COMPRISING: (A) AN ELONGATED, THICK WALLED, CYLINDRICAL BODY HAVING A PORTION OF ITS INTERIOR FORMED TO RECEIVE THE HEAD AND REAR PORTION OF A CARTRIDGE CASE, SAID BODY ALSO HAVING A PORTION OF ITS INTERIOR FORMED ON AN ENLARGED DIAMETER TO DEFINE AN INSERT-RECEIVING CAVITY, (B) A GENERALLY CYLINDRICAL INSERT MEANS SLIDABLY ENGAGED IN SAID CAVITY, SAID INSERT MEANS HAVING ITS INTERIOR FORMED TO THE GENERAL CONFIGURATION OF THE NECK AND CONE PORTION OF A CARTRIDGE CASE, (C) AT LEAST ONE END OF SAID BODY HAVING AN OFFSET STEP SURFACE MEANS DEFINED BY UPPER AND LOWER SURFACE MEANS, AND (D) SET SCREW MEANS IN SAID BODY FOR HOLDING SAID INSERT MEANS IN A PREDETERMINED POSITION. 